FR2562692A1 - Methods and devices for actuating an automatic unit as a function of the number of persons or objects present in an enclosure comprising accesses with two directions of passage - Google Patents

Abstract

The subject of the invention is methods and devices for actuating an automatic unit as a function of the number of persons or objects present in an enclosure comprising accesses with two directions of passage. A device according to the invention for automatically actuating illumination 3 of an enclosure 1 comprising an access 2 with two directions of passage, comprises two detectors S1, P1, S2, P2 placed one behind the other across the passage. Each detector is connected to one stage of a first monostable multivibrator M1 and to the other stage of a second multivibrator M'1. The output of the second stage of each multivibrator is connected to the input of a counting unit 4 by means of a diode D1, of a biasing resistor R6, of a differentiator circuit C1, R1, D2. The pulses emitted by each diode D2, D'2 are subtracted by the calculating unit 4 and compared to a predetermined number. An application is the automatic control of the lighting of a room.

Description

 Methods and devices for actuating an automated system as a function of the number of people or objects in an enclosure comprising two-way access.

 The present invention relates to methods and devices for actuating an automatic system as a function of the number of people or objects located in an enclosure comprising two-way access.

 Automatic systems are known which are activated by counting the number of objects in an enclosure. For example, some car parks in which cars enter by an entrance and exit by a different exit from the entrance, have entry and exit counters, which automatically activate a light signal indicating that the parking is full when the difference between the entries and exits reached a number equal to the number of places available.

 To date, there is no known device for actuating an automatic device as a function of the number of objects or people being in an enclosure when the inputs and the outputs are made by the same accesses. In this case, it is necessary to differentiate the inputs from the outputs using the direction of passage.

 An objective of the present invention is to provide means making it possible to actuate an automatic mechanism as a function of the number of people or objects being in an enclosure having one or more accesses through which the passages take place in both directions.

 For example, an objective of the present invention is to automatically control the extinction of the lights illuminating a room when this room is empty or else to control a modification of the appearance of a heating, an air conditioning, a ventilation depending on the number of occupants of a room, for example a performance hall or a public place.

 Another object of the present invention is to provide means for setting off an alarm if a person stays in a room longer than he should.

 We know devices that activate an alarm when they find the presence of a person in a room in circumstances where there should be no one. These devices generally include one or more detectors of the infrared or ultrasonic or electromagnetic wave type which directly detect the presence of a person in a room, but they do not include means for detecting inputs or outputs through one or more several two-way access.

The objectives of the invention are achieved by means of a method for actuating an automatic device as a function of the number of people or objects being in an enclosure comprising at least one access with a two-way passage, which method comprises the following operations
- each access is equipped with two successive passage detectors;
- We count the people or objects that cross said access in one direction by successively actuating the two detectors in a determined order;
- We count separately the people or objects that cross said access in the opposite direction, by successively actuating the two detectors in reverse order; - - we make the difference between the two numbers;
- And we activate said automation when this difference is equal to a predetermined number.

 In the case where the enclosure has several accesses with a double direction of passage, it must be possible to count the simultaneous passages through two different accesses.

 To this end, the coincidence between two passages in the same direction is detected through two different accesses, a passage is immediately recorded, the coincidence signal is delayed and a second passage is recorded which corresponds to said delayed signal.

 In the event that two people meet in front of the two passage detectors fitted to an access, avoid parasitic counting. when people separate without one of them crossing the access.

 To this end, a third passage detector is used which is placed in front of or behind the first two detectors to block information coming from the first or second of said detectors.

 A device according to the invention comprises, for each access into an enclosure, two passage detectors arranged one behind the other across said access and means for emitting a pulse corresponding to each passage of a person or a object which actuates the two detectors in a determined order and means for separately counting the pulses which correspond respectively to each direction of passage and it further comprises means for making the difference between the two numbers corresponding to each direction of passage and means for automatically controlling an operation when this difference reaches a predetermined value.

 The means for emitting a pulse corresponding to each passage of a person or an object through an access in a determined direction comprise a multivibrator monos table with two transistors and the base of each transistor is connected to one of the two receivers of the two detectors and when the first transistor is blocked, the base of the second transistor is biased under a voltage substantially equal to half the saturation voltage of said second transistor.

 The invention results in the control of an automatic system as a function of the number of people or objects which are in an enclosure in which one can enter by one or more accesses with two directions of passage.

 According to the invention, the number of people or objects that are in an enclosure is no longer determined by directly detecting the presence of people or objects in the room, which poses the problem of obstacles to direct detection, but by counting the inputs and outputs and making the difference between these two numbers.

 Unlike known methods, in which one counts the inputs by a one-way access and the outputs by a different one-way access, the methods and the devices according to the invention make it possible to differentiate the inputs from the outputs when the passages' take place in both directions through each access, which is the most frequent case in current practice.

 By way of non-limiting example, there may be mentioned as a possible application of a device according to the invention, the automatic switching on and off of the lighting of a room, a room or an assembly rooms or premises or a passage depending on whether these are occupied or unoccupied.

 It is also possible to use devices according to the invention for adjusting the rate of heating or air conditioning or ventilation of premises as a function of the number of occupants.

 The devices according to the invention can be used to activate any automation depending on the presence or absence of occupants or objects Gans an enclosure which can be part of a fixed building or of a vehicle for example of a boat, a train etc ...-.

 The following description refers to the appended drawings which represent, without any limiting character, an exemplary embodiment of a device according to the invention.

 FIG. 1 represents a block diagram of a device according to the invention, in the case of an enclosure with a single access.

 FIG. 2 represents a possible embodiment of one of the monostable multivibrators which operate in a device according to FIG. 1.

 FIG. 3 represents an embodiment of a counting neutralization circuit in the event of two people or two objects meeting on an access without any person or object entering the room.

 FIG. 4 represents a possible diagram of an anti-coincidence circuit making it possible to account for simultaneous passages through two different accesses.

 FIG. 1 represents an enclosure I having a single access 2, by which people, vehicles or objects enter or leave the enclosure. For example, enclosure 1 is a room or room, or a set of rooms with lighting 3 and the problem to be solved is to automatically turn on the lighting when the room or room or set of rooms does not is busier and turns it on automatically as soon as someone enters the room or set of rooms.

 Figure '1 shows, by way of illustration, an example in which the enclosure 1 comprises a single battery 2, but it could include several and, in this case, all the accesses could be equipped with identical devices.

 The coincidence detection system which is described with reference to FIG. 4 makes it possible to resolve the case where several people enter the room simultaneously or leave it simultaneously by several different accesses.

 Each access 2 is equipped with two passage detectors each composed for example of a light source S1, S2 and a photoelectric receiver P1, P2, which are placed one behind the other across the passage , so that a person entering or leaving successively cuts the two light beams going from each source to the corresponding receiving cell.

The photocells could be replaced by any equivalent passage detector, for example by two successive pressure detectors placed on the ground in the passage or by induction gantries, or by mechanical or electrical tabs, etc. Each receiver P1, P2 is connected to a preamplifier
A1, A2.

 The device comprises two monostable multivibrators M1 and M'1 each comprising two stages designated respectively by T1 and T2 for the monostable M1 and T'1 and T'2 for the monostable M'2.

The output of the amplifier A1 is connected through an inverter I1 on the first stage T1 of the monostable M1, while the output of the amplifier A2 is connected on the second stage T2 of the monostable N1. The output of stage T2 is connected to a diode D1 mounted in the opposite direction. The anode of this diode is connected to a bias resistor R6 and to a differentiator circuit composed of a capacitor Cl and a resistor
Ri separated by a diode D2 mounted in the direct direction and also on a polarization resistance R6. The cathode of diode D2 is connected to the counting input of a pulse counter 4.

 The connections of the outputs A1 and A2 on the input terminals of the second monos table M'l are inverse of the connections on the first monostable, that is to say that the output of A2 is connected through an inverter I2 on the first stage T'l of the second monostable M'1 and the output of Al is connected to the second stage T'2 of the second monostable M'1. The output of T'2 has the same components as the output of T2, namely a diode D'1, a bias resistor R'6 and a differentiator circuit C'1, R'1, the components of which are separated by a diode Di2.

 The cathode of the diode D'2 is connected to the countdown input of the counter 4.

 The counter 4 is an up-down counter which adds the pulses which the diode D2 passes and which subtracts the pulses which the diode D'2 passes.

 Alternatively, two separate pulse counters can be used to separately count the pulses that pass through the diodes D2 and D'2 and a subtractor circuit that differentiates between the numbers of pulses counted by the two counters.

 According to another variant shown in dotted lines, the cathode of the diode D'2 is connected through an inverter I3 on the same input as the output of D2 of a counting unit which directly differentiates between the positive pulses and the pulses negative.

 The stages of counter 4 are connected to a comparator circuit 5 which compares the number recorded in counter 4 or in the subtractor with a predetermined number, for example zero in the case of the figure.

 When the number zero appears, the output of the comparator 5 possibly resets the stages of the counters 4 to zero and controls an electronic switch or a relay 6, for example a thyristor or a triac, which automatically extinguishes the lamp 3.

 A manual switch 8 enables the switch 6 to be energized at night and isolate it during the day. This manual switch can be replaced by a switch controlled automatically by a daylight sensitive cell. A manual switch 9 can be interposed between the comparator 5 and the switch 6 to disconnect the counting device according to the invention from the lamp control in order to leave the possibility of operating the lighting voluntarily in the absence of occupants in the room.

 FIG. 2 is a diagram of an embodiment of a monostable M1 or M'1. We find in Figure 2 the preamplifiers Al and A2. The diagram of a monostable multivibrator is well known to electronics engineers and it is not necessary to explain it in detail. We see in Figure 2 the two stages of the monostable consisting of two transistors T1 and T2 of NPN type. The collector of each transistor is connected to the base of the other transistor through a capacitor respectively C2 and C3, the latter being mounted in parallel with a resistor R3.

 The operation is as follows.

In the state of equilibrium without external stress, the transistor T1 conducts and T2 is blocked. When a person or an object enters the enclosure 1 through the door 2, the light beam emitted by the source S1 is first intercepted. The receiver P1 transmits a positive step which is transformed into a negative step by the inverter I1. The transistor T1 is blocked. Let VB, Vc, VB 'and Vc' be the base and collector voltages of the two transistors. The base
B 'is connected to ground by a resistor R4 and the collector C is connected to the positive voltage by a resistor R5. These two resistors as well as the resistor R3 are chosen so that when T1 is blocked, T2 conducts but the voltage on the base
B 'of T2 does not then exceed about half of the saturation value. T2 therefore conducts without being saturated and Vc ′ remains greater than the voltage Vo of polarization of the anode of Dl which remains blocked.

 If the person or the object goes back without intercepting the ray coming from S2, the transistor T1 becomes saturated again, the transistor T2 is blocked again and nothing happens.

If the person or the object continues to advance and intercepts the light ray coming from S2, A2 emits a positive step which is sent on the base B 'of T2. This positive voltage step of amplitude equal to half the base saturation voltage
B 'of transistor T2, is added to the potential induced on B' by blocking T1.

 The transistor T2 starts to conduct and Vc drops below Vo. The diode D1 then becomes conductive, which gives rise on its anode to a negative step -which is differentiated by the differentiating circuit CIRI. The leading edge, which is negative, is eliminated by D2. If the person or object continues to advance and no longer interprets the light ray from S2, the positive rung emitted by P2 through A2 is interrupted. The transistor T2 leads again to a reduced level, the negative step on the anode of D1 ends and by differentiation through C1, D2 and R1, a positive pulse is obtained. This is sent to the counting input of counter 4 which records a passage. At the same time, the rise in potential at C 'is retransmitted to the base B of T1 through C2. Ti is renewed again while T2 is blocked. Let us now examine in FIG. 2, what happens if an exit takes place through the access 2, that is to say if the light ray emitted by S2 is intercepted first.

 In this case, A2 emits a positive step which arrives at the base B 'of T2 but this step has a value equal to half of the saturation voltage of T2., So that it does not saturate T2 but, on the other hand , T1 is blocked. If the person or the object continues to progress, it intercepts the light ray coming from S1. Al then emits a positive edge which is inverted by the inverter I1 but since T1 is already blocked, nothing happens.

 It can therefore be seen that the monostable M1 conforming to FIG. 2, makes it possible to record the inputs but does not record the outputs.

 Conversely, the monostable M'1 which is mounted in the opposite direction to the monostable M1, records the outputs and does not record the inputs.

 The above description starts from the assumption that the receptors F1 and P2 lead to an increase in voltage, which amounts to emitting a positive step when the light ray which it normally receives is intercepted. If P1 and P2 are photoconductive cells, one of the terminals of which is positively polarized, this is obviously the case, but this example is obviously not limiting. In the opposite case, it suffices to move the inverters I2 and I2.

A possible error is that where people meet in an access 2 and start to discuss in the access then separate without crossing the access. The light rays emitted by Si and S2 having been intercepted then restored, there is a significant risk of obtaining an incorrect counting pulse in the direction of the inputs or outputs. To avoid this risk, we use the variant shown in dotted lines on the face. I which includes a third passage detector 53, P3 of the same type as the other two detectors, that is to say composed of a transmitter S3 and a photoelectric receiver P3 which is placed either in front , or behind the other two detectors S1, Fl ;; S2, P2
The links of that of the receivers F1 and P2- which is closest to the receiver P3, with the monostable multivibrators Ml, M1 'are made through a door whose trigger is controlled by
P3, so that when the third passage detector is actuated, said door is blocked.

 FIG. 3 represents a possible embodiment of such a trigger door when S3, P3 is placed behind the two passage detectors S1, P1 and S2, P2. This gate is in fact constituted by the amplifier A2, which is here constituted by a PNP transistor T3 whose emitter here acts as a trigger.

 The receivers P2 and P3 are photoconductive cells which connect the positive bias voltage respectively to the base and to the emitter of T3.

 When these two cells conduct, that is to say when neither of the two passage detectors S2, P2 and S3, P3 is actuated, the transistor T3.is blocked, because although it can conduct its base through its transmitter is brought to positive potential.

 If the passage detector S3, P3 is actuated, which necessarily happens if two people park in front of the two passage detectors S1, P1 and S2, P2, provided that S3, P3 is not too far from S2, P2, the cell photoconductive P3 no longer conducts and transistor T3 is blocked by its emitter circuit. Therefore, the positive scale induced by the action on the detector 52, P2, cannot be transmitted by A2 to the monostable multivibrators M1 and M1 '.

The inhibitory action of P3 on the conduction of T3 is suppressed when the person who parked in front of S3, P3 advances towards
S1, P1, moving in front of s2, P2. The photoconductive cell P3 then begins to conduct, the transistor T3 having its emitter positively polarizes and its base to ground begins to conduct and on its collector appears a positive step which is transmitted to the monostable multivibrators M1 and M1 '.

When the person moves in the opposite direction, the photoconductive cell P3 plays its inhibitory role only to shorten the positive step emitted by P2 through T3, but cannot harm the counting as it appears clearly from the explanations given above on the operation of the monostable multivibrator M1. it is obvious that the reasoning followed here still applies if people are replaced by objects, for example carts'
Furthermore, it is clear that the previously described arrangement could be used with P1 replacing P2 in the event that the passage detector S3, P3 is placed in front of the two passage detectors S1, P1 and S2, P2
If the enclosure 1 has several accesses, it is necessary to resolve the case where several people or several objects enter or exit simultaneously through two different accesses.

 The case where several passages take place simultaneously through the same access cannot occur if the width of the accesses is such that several passages cannot take place simultaneously, which is the general case for the passage of people in a normal door opening .

 If the width of the opening allows the passage of several people at the same time, the access is divided into several corridors which are treated as separate accesses.

 FIG. 4 represents an exemplary embodiment of a circuit which makes it possible to resolve the case of a simultaneous passage through two different accesses. It is possible to generalize a case of more than two accesses.

 The references D2-1 and D2-2 represent for example the two diodes located respectively at the output of the two single tables H1 equipping two accesses 2 of the same part.

 FIG. 4 shows only the circuits located at the output of the monostables M1 of the two accesses. Identical circuits also equip the outputs of the monostables M'1 of the two accesses.

 The device has three AND gates G1, G2 and G3 with two inputs each. The outputs D2-1 and D2-2 are connected respectively to the two inputs of G2 and each of them is connected respectively to one of the inputs of G1 and G3.

 The second inputs of G1 and G3 are connected to the output of a delay circuit 7 such as an L.C. circuit. The outputs of the three doors G1, G2 and G3 are connected to the three inputs of an OR gate 03.

 The output of the OR gate 03 is itself connected to the delay circuit 7.

The circuit has a second OR 04 gate with three in trées which are connected respectively to the outputs of the diodes.
D2-1 and D2-2 and on the lane of the delay circuit 7. The output of gate 04 is connected to the counting input of the counting unit 4 which registers the inputs in the case of FIG. 1.

 The operation is as follows.

 If an isolated passage takes place, the corresponding positive pulse is sent by one of the diodes D2-1 or D2-2 on gate 04 and an entry is recorded in the counting unit 4.

 If two passages take place simultaneously, gate 04 receives two simultaneous pulses and the counting unit records a first entry.

 At the same time the gate G2 detects a coincidence and it sends a positive pulse through the OR gate 03. This positive pulse is delayed by the circuit 7 compared to the initial pulses emitted simultaneously by the diodes D2-1 and D2-2. delay pulse is received by gate 04 which transmits it to the counting unit 4 which registers a second input.

 It may happen that the delayed pulse is in turn simultaneous with another pass. To resolve this particular case, the gates G1 and G3 were added to the circuits and the output of the delay circuit 7 was looped back to an input of each of these gates.

 The second input of each gate G1 and G3 is connected respectively to the cathode of the diodes D2-1 and D2-2. One of the doors G1 or G3 detects the coincidence between the delayed signal and the pulse emitted by the second pass and the coincidence signal is again delayed and recorded in the counting unit 4 on the condition that it does not coincide not with a new passage in which case a new loop is traversed.

 In the case where an access 2 is used to connect two speakers, the inputs into one of the speakers are outputs for the other speaker and, in this case, the same device according to the invention can be used to count both the inputs in one enclosure and the outputs of the other enclosure.

 To be able to easily remedy counting errors which could be due to false counting of entrances or sorting in very specific passage cases depending on the sophistication of the passage detectors used or in the event of a power failure, it is advantageous to have a command to reset the counting unit 4 outside the enclosure near an access. It is also possible to place inside the enclosure a leveling of the counting unit 4, which makes it possible to record therein a number equal to the actual number of occupants of the enclosure. This refresher can for example be of the type which equips the resetting of the time or date of quartz watches.

Claims (10)

 1. Method for actuating an automatic system as a function of the number of people or objects being in an enclosure (I) comprising at least one access (2) with a double direction of passage, characterized in that each access is equipped with two successive passage detectors (Si, P1; S2, P2); the persons or objects which cross said access in one direction are counted by successively actuating the two detectors in a determined order; the persons or objects which cross said access in the opposite direction are counted separately, by successively actuating the two detectors in reverse order;  we make the difference between the two numbers and we activate said automation when this difference is equal to a predetermined number.  2. Method according to claim 1 for actuating an automation as a function of the number of people or objects being in an enclosure comprising several two-way accesses of  eS passage allowing to count the simultaneous passages through two different accesses, characterized in that the coincidence between two passages in the same direction is detected Through two different accesses, a passage is immediately recorded, the signal is delayed coincidence and a second pass is recorded which corresponds to said delayed signal.  3. Method according to any one of claims 1 and 2 for actuating an automation without parasitic effect in the case where two people or two objects meet in front of the two passage detectors (Si, F1; S2, P2) of an access, then separate without one  of the two crosses the access, characterized in that a third passage detector (53, -F3) is used which is placed in front of or behind the first two detectors to block information coming from the first or second of said said detectors.  4. Device for actuating an automatic device as a function of the number of people or objects located in an enclosure (l) which comprises at least one access (2) with a double direction of passage, characterized in that it comprises, for each access (2), two passage detectors (S1, Fl ;; S2, P2), arranged one behind the other across said access, means for emitting a pulse corresponding to each passage of a person or an object which actuates the two detectors in a determined order and means for separately counting the pulses which correspond respectively to each direction of passage and it further comprises means for making the difference between the two numbers corresponding to each direction of passage and means for automatically controlling an operation when this difference reaches a predetermined value.  5. Device according to claim 4, characterized in that said means for emitting a pulse -corresponding to each passage of a person or an object through said access (2) in a determined direction, comprise a monostable multivibrator (Ml ) to two transistors (Ti, T2) and the base of each transistor is connected  unequivocally on the receiver (Pl or P2) of one of said two detectors which equip each access and when the first transistor is blocked, the base of the second transistor is biased under a voltage such as a passage through the access in the opposite direction gives rise to no impulse.  6. Device according to claim 5, characterized in that said two receivers (fol, P2) equipping each access are connected in a one-to-one manner on the two stages (Tl, T2) of a first single-table multivibrator (Ml) which emits a positive impulse at each entry into the enclosure and are also connected so  one-to-one on the stages (T'l, T'2) of a second monostable multivibrator (M '1) which emits a positive pulse at each output of the enclosure and the connections of said receivers on the two stages of the second multivibrator are reversed connections on the two stages of the first multivibrator.  7. Device according to claim 6, characterized in that each access (2) comprises a third passage detector (S3, P3) which is arranged either in front or behind the other two detectors (S1, Fl; S2, P2 ) and the connection of the first receiver if it is in front or of the second receiver if it is behind, with said monostable multivibrators (Ml, M'l), passes through a door (Al or A2) with trigger, which is controlled by the receiver (P3) of said third detector, so that said door is blocked if this third detector is actuated.  8. Device according to any one of claims 4 to 7, characterized in that said means for separately counting the pulses corresponding to each direction of passage and for making the difference between the two numbers of pulses comprise a counter for counting pulses (4) and the counting and down counting inputs respectively of said up-down counter are connected to the output (D2) of the pulse transmitter corresponding to the inputs into the enclosure and to the output (D'2) of the transmitter d corresponding pulses  dant at the outputs of the enclosure and said up-down counter (4) is connected to a comparator (5) which compares the number recorded in said up-down counter with a predetermined number and which automatically controls a switch (6) actuating an automation when said predetermined number is reached.  9. Device according to any one of claims 4 to 8, characterized in that it comprises means making it possible to count simultaneous passages in the same direction through several different accesses, which means include: (A) an AND gate ( G2) with two inputs on each of which is unequivocally connected the  output (D2-l or D2-2) of one of two pulse transmitters which each equip an access for a determined direction of passage, (B) a delay circuit (7) such as an LC circuit whose l input is connected to the output of said AND gate (G2) and- (C) an OR gate (04) on the inputs of which the outputs are connected on the one hand  said pulse transmitters (D2-1, D2-2) and on the other hand the output of said delay circuit (7), the output of said OR gate being connected to a counting unit (4).  10. Device according to claim 9, characterized in that it further comprises two other AND gates (Cl, G3) with two inputs, the output of said retarder circuit being connected to an input of each of these two gates, l the other input of each of these two doors being connected in a one-to-one manner on the output (D2-l or D2-2) of one of said two pulse transmitters and the outputs of the three doors AND (Cl, G2, G3) being connected to an OR gate (03) whose output is connected to the input of said retarder circuit (7).